Coin cleaning apparatus

Abstract

A coin cleaning and grinding apparatus includes a conveyor for conveying coins, two drive rollers of urethane sponge having a urethane hardness between 70 and 90 degrees, and a pair of primary grinding rollers and a pair of secondary grinding rollers of urethane sponge. The primary grinding rollers are supported rotatably and downstream from the conveyor. One of the primary grinding rollers is positioned lower than the other. The lower primary grinding roller is in compressive contact with the higher primary grinding roller and one of the drive rollers. The secondary grinding rollers are supported rotatably and downstream from the primary grinding rollers. One of the secondary grinding rollers is positioned lower than the other. The lower secondary grinding roller is in compressive contact with the higher secondary grinding roller and the other drive roller. A sprinkling plate is positioned at an angle above the grinding rollers. The sprinkling plate has sprinkling holes through which abrasive liquid can be sprinkled. The holes are formed above the grinding rollers, respectively, upstream from the axes of the grinding rollers, respectively. The sprinkling plate has drip-prevention grooves formed in its underside.

I claim:  
     
       1. A coin cleaning and grinding apparatus comprising: 
       a conveyor for conveying coins having a discharge end;  
       first and second drive rollers supported rotatably and horizontally in parallel with each other;  
       a pair of first and second primary cleaning/processing rollers mounted rotatably and downstream from the discharge end of the conveyor, the primary cleaning/processing rollers extending in parallel with the drive rollers, the first primary cleaning/processing rollers being positioned lower than the second primary cleaning/processing roller, the second primary cleaning/processing roller being in compressive contact with the first primary cleaning/processing roller and the first drive roller;  
       a pair of first and second secondary cleaning/processing rollers supported rotatably and downstream from the primary cleaning/processing rollers, the secondary cleaning/processing rollers extending in parallel with the drive rollers, the first secondary cleaning/processing rollers being positioned lower than the second secondary cleaning/processing roller, the first secondary cleaning/processing roller being in compressive contact with the second secondary cleaning/processing roller and the second drive roller; and  
       a sprinkling plate positioned at an angle above the primary and secondary cleaning/processing rollers;  
       the sprinkling plate having first and second rows of sprinkling holes for sprinkling abrasive liquid onto the cleaning/processing rollers, the first row being formed above and in parallel with the primary cleaning/processing rollers upstream from axes of the primary rollers, the second row being formed above and in parallel with the secondary cleaning/processing rollers upstream from axes of the secondary rollers.  
     
     
       2. The cleaning and grinding apparatus according to  claim 1 , wherein the sprinkling plate has first and second drip-prevention grooves formed in an underside thereof, the first and second grooves extending along and downstream from the first and second rows of sprinkling holes, respectively, and wherein the grooves are rectangular in vertical section. 
     
     
       3. The cleaning and grinding apparatus according to  claim 1 , wherein the cleaning/processing rollers each include a shaft of vinyl chloride and a grinding sleeve made of urethane sponge, the sleeve being press-fitted around and adhering to the shaft. 
     
     
       4. The cleaning and grinding apparatus according to  claim 1 , wherein the drive rollers are made of urethane sponge having a urethane hardness of between 70 and 90 degrees.